1. Field of the Invention
The present invention concerns a high purity chemical delivery system, and, more particularly, a high purity chemical delivery system enabling a rapid clean out and purge of any high purity chemical residues.
2. Description of Related Art
High purity chemical delivery systems are typically composed of manifolds having diaphragm valves and low dead space connectors. In the semiconductor industry, for instance, low vapor pressure high purity chemicals such as tetrakis (dymethilamino) titanium (TDMAT), tetrakis (diethylamino) titanium (TDEAT), tantalum pentaethoxide (TAETO), copper hexafluoroacetylacetonate-trimethylvinylsilane (Cu(hfac)TMVS), tetramethyltetracyclosiloxane (TMCTS), tetraethyl ortosilicate (TEOS), and trimethylphosphate (TMP) are delivered from primary storage canisters to process tools or to secondary storage canisters by means of manifolds that incorporate a plurality of diaphragm valves and that regulate the flow of the chemicals during ordinary process conditions and the flow of pressurized gases and of vacuum during purge cycles. These manifolds are detachably connected by low dead space connectors, such as VCR and low obstruction fittings, in order to minimize any entrapments of the high purity chemical within the dead spaces of the connectors and thereby reduce purge cycles.
When a storage container has exhausted the supply of high purity chemical and must be replaced, the delivery system connected to the container must be thoroughly purged after the new container is installed, in order to remove any impurities and any ambient gases that have entered the system during the canister replacement process. Due to the high purity levels required, these purge cycles are extremely time consuming causing manufacturing costs to increase due to the related manufacturing down-time and to the costs of the purge materials.
Therefore, there is a need for a high purity chemical delivery system minimizing the time required for clean out and purge.